Latching system

ABSTRACT

An automatic latching system for pallets and the like including latching devices, each arranged so a pallet can move thereover to depress an upwardly biased star wheel until a pallet is positioned on one or both sides of the latching device, at which time the spokes of the upwardly extended star wheel hold and restrain the pallets from vertical and horizontal movement.

0 United States Patent 11 1 1111 3,759,476 Goodwin y Sept. 18, 1973 [54]LATCHING SYSTEM 3,698,679 10 1972 Lang al. 248/36] R 1 1 Inventor:Walter Goodwin, Sim Made, 33321333 32313 E$2IZZi1i31.... ""3333: 333%Calif.

[73] Asslgnee: g i gfizg gg gzf i Primary Examiner-Edward C. AllenAtt0rney-Walter J. Jason et al. [22] Filed: Feb. 18, 1972 [21] Appl.No.: 227,416

[57] ABSTRACT 52 [1.8. 01 248/361 R An automatic latching system forpallets and the e [51] hit. CL B65d 19/38 including latching devices,each arranged so a pallet [58] Fleld of Search 248/361 R, 1 19 R; canmove thereover to depress an upwardly biased star 292/DIG' 2801 210;105,366 366 wheel until a pallet is positioned on one or both sides D ofthe latching device, at which time the spokes of the upwardly extendedstar wheel hold and restrain the pal- [56] References C'ted lets fromvertical and horizontal movement.

UNITED STATES PATENTS 3,460,792 8/1969 Brenner et a1. 248/119 R 8Claims, 6 Drawing Figures PATENTED SEN 8 I973 SHEET 1 OF 3 PATENTED SEN8 I975 sum 2 u; 3

Pmmmsmaln SHEET 3 [IF 3 1 LATCHING SYSTEM BACKGROUND OF THE INVENTIONMost of the prior art pallet latches for restraining pallets from fore,aft, and vertical movement are not usable in automatic powered loadingsystems. This is because the prior art latches must be manually actuatedto latch or unlatch the pallets in place. The few prior art automaticlatches are complicated, heavy and expensive and include special springand cam arms actuated by the pallet or other power actuated means toraise and lower retention means for the latch. In addition, suchautomatic latches have not proved to be fail indicative. Therefore, eventhough they are designed to work automatically, personnel must bepresent to assure that the latches are operating properly. This defeatsone of the primary objects of such latches which is to reduce themanpower required to handle cargo. Also, it makes such latchesunsuitable for use with automated systems for loading containers andpallets in a tunnel, such as the belly of an aircraft, where no space isavailable to allow a man to move past the loaded pallets for inspectionof the latches in use.

SUMMARY OF THE INVENTION The present invention solves the problemsheretofore unsolved by the prior art latches by providing a systememploying automatic latches which are lightweight, in-. expensive and inthe remote chance of failure, indicate such failure so that aircraft inwhich they are used are never endangered by loose pallets. The presentlatches provide vertical and horizontal restraint to a pallet,automatically lower as each pallet goes by and then rebound to raisedpositions that enable the restraint of pallets forward and/or aft ofthe. latches.

Each latch includes a four spoke star wheel which is mounted forrotation on an upwardly biased linkage assembly. A pallet moving overthe latch contacts a spoke of the star wheel, rotates it and pushes thestar wheel beneath the pallet. Bias means associated with the star.

wheel supporting linkage assembly force two of the spokes up against thebottom of the pallet. As the trailing edge of the pallet travels overthe latch, the bias means force the star wheel upward to pivot about theend of the pallet and regain its raised position. Once the star wheelhas been pivoted to the raised position, it is in proper attitude tolatch the forward and aft pallet or to again pivot out of the way as apallet is moved thereover. When pallets are in position on both sides ofthe star wheel, it is fixedthereby to restrain the pallets. In addition,once one or two pallets have been positioned in engagement with the starwheel of the latch, a safety lock can be moved to assure that the starwheel is locked in its pallet restraining position. The safety lock canonly be moved to its locking position when the star wheel is in itsproper pallet restraining position. It is preferable that positive meansare provided to connect the safety locks of associated latches togetherso the failure to latch of one or more of the latches is immediatelydiscoverable through the impossibility of moving the positive lockconnecting means to a predetermined locked position.

It is therefore an object of the present invention to provide anautomatic latching system for pallet assemblies in aircraft.

Another object is to eliminate the need for manual manipulation orinspection of latches within an aircraft.

' is not substantially heavier than Another object is to provide anautomatic latch which can be used to restrain pallet assemblies and thelike within a tunnel configuration where access to the latch is limitedonce the loaded pallet assemblies have been positioned therein. 6

Another object is to provide an automatic latch which is failindicating, economical, reliable and which conventional manual latchesfor such pallets.

These and other objects and advantages of the present invention willbecome apparent after considering the following detailed specificationwhich covers a particular embodiment of the present invention inconjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the latchingdevice of the present latch system invention;

FIG. 2 is a side view of the latching device of FIG. 1 in position toreceive pallet assemblies;

FIG. 3 shows the latching device of FIG. 2 with a pallet assembly movingthereover;

FIG. 4 is a side view of the latching device of FIG. 2 with its starwheel in the worst possible condition during the latching of twoadjacent pallet assemblies;

FIG. 5 is a side view of the latching device of FIG. 2 in a lockedcondition, restraining two adjacent pallet assemblies; and

FIG. 6 is a plan view of the floor of an aircraft fuselage with alatching system constructed according to the present invention installedtherein.

DESCRIPTION OF THE PRESENT EMBODIMENT Referring to the drawings moreparticularly by reference numbers, number 10 in FIGS. 1 and 2 denotes anautomatic latching device constructed according to the present inventioninstalled in the floor 12 of an aircraft. The latch 10 includes a starwheel 14 having spokes 16, 18, 20 and 22. The star wheel 14 is mountedfor rotation on an upwardly biased linkage assembly 24 by means of ashaft 26 which is held in place by means such as spring keepers 28 and30. The linkage assembly 24 includes link arms 32, 34, 36 and 38 whichare connected together by the shaft 26 at their upper ends 40, 42, 44and 46, respectively. The ends 40, 42, 44 and 46 of the link arms 32,34, 36 and 38 extend upwardly so that the arms cannot interfere with theaction of the star wheel 14 to be described hereinafter. The oppositeends 48 and 50 of the link arms 32 and 34, respectively, are connectedtogether by means of a shaft 52 which extends therebetween and ispartially restrained in horizontally slotted openings 54 and 56 in abifurcated base member 58. A horizontally slotted opening 60 in anopposite base member 62 partially restrains a shaft 64 connecting theopposite ends 66 and 68 of links 36 and 38 in a similar manner. Theinboard ends 69 (FIG. 3) of the slotted openings 54, 56 and 60 serve asstops to take all fore, aft and upward loads and to position the starwheel 14 at the correct locking height. The base members 58 and 62 are.connected to the floor structure 12 and the slotted openings 54, 56 and60, provide clearance so the link arms, 32, 34, 36 and 38 along withtheir connected star wheel 14 can be depressed downwardly against theupward biasing action of a pair of springs 70 and 72 connected about theshaft 52. Ends 74 and 76. of the springs 70 and 72 are restrained by thefloorstructure 12 while the other ends thereof, 78 and 80, are connectedto the link arms 32 and 34 by means of inwardly extending rods 82 and84.

As shown in FIG. 3, the moving of a pallet 86 over the latch causesengagement between the pallet 86 and one of the spokes 16. This causesthe star wheel 14 to rotate away from the pallet 86 until the adjacentspoke 18 comes in contact with the bottom surface 88 thereof. Thecontact prevents the star wheel 14 from further rotation and the weightof the pallet 86 thereafter depresses the star wheel 14 and itsconnected linkage assembly 24 against the upward biasing action of thesprings 70 and 72. Once the pallet 86 has moved past the star wheel 14as shown in FIG. 4, the biasing action of the springs 70 and 72 causesthe star wheel 14 to again assume its raised position as limited by theslotted openings 54, 56 and 60 and the linkage means 24. As the end ofthe pallet 86 passes the centerline 90 of the shaft 26, the spoke 16 isrotated under the pallet while the adjacent spoke 18 is rotatedthereabove. If the pallet 86 is not restrained adjacent the star wheel14 and is moved away from the latch 10, the next pallet 92 will causethe same action of the star wheel 14, However, when the pallet 86 isrestrained adjacent the star wheel 14, as shown in FIG. 4, the nextpallet 92 strikes the spoke of the star wheel 14 causing it to rotate tothe position shown in FIG. 5. The upward pointing spokes 18 and 20thereafter restrain both pallets 86 and 92. The axial centerline 90 ofthe shaft 26 and star wheel 14 is always restrained below thecenterlines 94 of the pallets so that the pallets always tend to moveover the star wheel 14 and it is never possible for a pallet to tuckunder the shaft 26 and cause a jammed condition.

Rollers 96 and 98 are provided on the opposite sides of the star wheel14. In conjunction'with the floor rollers 99, they support the palletsand further assure that the centerlines 94 of the pallets never dropbelow the centerline 90 of the star wheel 14 and shaft 26. The rollers96 and 98 also prevent a heavy pallet from uplifting to depress a lightpallet on the other side of star wheel 14. The roller 96 is mounted forrotation to a sta-- tionary member 100 while the roller 98 is mountedfor rotation to a safety locking member 102. The locking member 102 isrestrained to be slidable a predetermined distance by suitable meanswhich are shown as a rail 103 and a stud 104. The locking member 102 hasa relatively flat abutment surface 105 which can he slid under the starwheel 14 when it is in the x position shown in FIG. 5. The abutmentsurface 105 engages with the two downward pointing spokesfl6 and 22 toprevent rotation and/or depression of the star wheel 14. This fixes thetwo opposite upward pointing spokes 18 and 20 to restrain adjacentpallets from longitudinal or upward motion no matter whether pallets areon one or both sides of the star wheel 14. The abutment surface 105 hasonly slight clearance with the spokes 16 and 22. If the star wheel 14 isin other than the proper x position, the end 106 of the locking member102 engages the closest out of position spoke to restrict further motionof the locking member 102.

As shown in FIG. 6, a purality of latches 10 are installed on the floor12 of the aircraft to form the latch system 108. The latches 10 arepositioned along the floor 12 in lateral and longitudinal alignment. Thesafety locking members 102 of each set for longitudinally alignedlatches 10 are preferably connected together by positive linkage means110. The linkage means 110 are usually operated by means of levers 112or position indicating solenoids 1 13 to enable the locking andunlocking of each longitudinal set of latches 10 separately or inunison. The levels 112 may be manually operated from any suitablelocation which is accessible with a full cargo load such as the doorway114. In the alternative, the locking members 102 may be connected bylateral acting linkage (not shown) which allows a loading crew toleavespaces in the pallet string. The improper latching of the starwheel 14 of any of the latches 10 is immediately discoverable throughthe inability to move a lever 112 to the locking position or by theinability of a solenoid 113 to move the linkage means 1 10.

It is usual practice to provide three or more longitudinal sets oflatches 10. Usually less than all of the longitudinal latch sets aresufficient to hold the pallets and therefore should one latch set failto lock, the cargo pallets can still be secured by the latches 10 of theother sets and no unloading operation need take place.

Once the cargo pallets reach their destination, the latches 10 areunlocked by moving all of the locking members 102 back to the positionshown in FIG. 1. The pallet in the doorway 114 is removed first. As thedoorway pallet moves away from the spokes of the adjacent star wheels14, the wheels 14 are free to rotate and therefore the next pallet isreleased and can also be removed by means such as the powered rollers116. The latches 10 then release the pallets one at a time in order.

-Thus there has been shown and described a novel latching system whichfulfills all of the objects and advantages sought therefor. Manychanges, alterations, modifications, and other uses and applications ofthe subject latching system will become apparent to those skilled in theart after considering this specification and the accompanying drawings.All such changes, modifications, variations and other uses andapplications which do not depart from the spirit and scope of theinvention are deemed to be covered by the invention which is limitedonly by the claims that follow.

What is claimed is:

1. A latching system for pallets and the like including:

at least one latch assembly, said latch assembly having a base, linkagemeans connected to said base, bias means, and a star wheel memberconnected for rotation about an axis to said linkage means,

saidv star wheel being biased upwardly to a predetermined position bysaid bias means, said star wheel having spokes which extend radiallyoutward from the axis at intervals thereabout for engaging and latchingpallets to said assembly and said linkage means being comprised of firstand second pairs of links, said links having first and second endportions and being connected together and to said star wheel at saidfirst ends thereof, said pairs of links extending away from said starwheel in generally opposite directions, said base including means toconnect said link second ends for rotation and restricted translation tosaid base.

2. The latching system defined in claim 1 including:

means to support the pallets at a predetermined distance from said base,said predetermined support distance being related to said star wheelpredetermined position so the centerline of the pallet edges, is heldfurther from said base than the axis of rotation of said star wheel.

3. The latching system defined in claim 2 wherein said star wheel ismounted for rotation substantially 90 from the loading and unloadingdirection of the pallets.

4. A latching system for pallets and the like including at least onelatch assembly, said latch assembly having:

a base;

linkage means connected to said base;

bias means;

a star wheel member connected for rotation about an axis to said linkagemeans, said star wheel being biased upwardly to a predetermined positionby said bias means, said star wheel having outwardly extending spokesfor engaging and latching pallets to said assembly which extend radiallyoutward from the axis of rotation of said star wheel at substantially 90intervals thereabout;

means to support the pallets at a predetermined distance from said base,said predetermined support distance being related to said star wheelpredetermined position so the centerline of the pallet edge is heldfurther from said base than the axis of rotation of said star wheel,said star wheel being mounted for rotation substantially 90 from theloading and unloading direction of the pallets; and

a locking member movable along said base and in eluding an upwardlyfacing abutment surface, said abut-ment surface being a predetermineddistance above said base and being engagable with two of said spokeswhen said star wheel is in its predetermined position, said spokes areabout 45 to said base and said locking member is moved between said baseand said star wheel, to prevent substantial rotation and depression ofsaid star wheel.

5. The latching system defined in claim 4 wherein said locking memberincludes an upward facing roller for engaging a pallet thereover toassure the pallet thereover is no closer than a predetermined distanceto said base.

6. The latching system defined in claim 4 including:

means to positively connect locking members of selected latch assembliesso said locking members move in unison.

7. The latching system defined in claim 6 wherein said selected latchassemblies have the axes of rotation of' said star wheels thereof insubstantial alignment.

8. The latching system defined in claim 6 wherein said selectedlatchassemblies are substantially aligned in the direction of movement of thepallets.

1. A latching system for pallets and the like including: at least one latch assembly, said latch assembly having a base, linkage means connected to said base, bias means, and a star wheel member connected for rotation about an axis to said linkage means, said star wheel being biased upwardly to a predetermined position by said bias means, said star wheel having spokes which extend radially outward from the axis at 90* intervals thereabout for engaging and latching pallets to said assembly and said linkage means being comprised of first and second pairs of links, said links having first and second end portions and being connected together and to said star wheel at said first ends thereof, said pairs of links extending away from said star wheel in generally opposite directions, said base including means to connect said link second ends for rotation and restricted translation to said base.
 2. The latching system defined in claim 1 including: means to support the pallets at a predetermined distance from said base, said predetermined support distance being related to said star wheel predetermined position so the centerline of the pallet edges is held further from said base than the axis of rotation of said star wheel.
 3. The latching system defined in claim 2 wherein said star wheel is mounted for rotation substantially 90* from the loading and unloading direction of the pallets.
 4. A latching system for pallets and the like including at least one latch assembly, said latch assembly having: a base; linkage means connected to said base; bias means; a star wheel member connected for rotation about an axis to said linkage means, said star wheel being biased upwardly to a predetermined position by said bias means, said star wheel having outwardly extending spokes for engaging and latching pallets to said assembly which extend radially outward from the axis of rotation of said star wheel at substantially 90* intervals thereabout; means to support the pallets at a predetermined distance from said base, said predetermined support distance being related to said star wheel predetermined position so the centerline of the pallet edge is held further from said base than the axis of rotation of said star wheel, said star wheel being mounted for rotation substantially 90* from the loading and unloading direction of the pallets; and a locking member movable along said base and including an upwardly facing abutment surface, said abut-ment surface being a predetermined Distance above said base and being engagable with two of said spokes when said star wheel is in its predetermined position, said spokes are about 45* to said base and said locking member is moved between said base and said star wheel, to prevent substantial rotation and depression of said star wheel.
 5. The latching system defined in claim 4 wherein said locking member includes an upward facing roller for engaging a pallet thereover to assure the pallet thereover is no closer than a predetermined distance to said base.
 6. The latching system defined in claim 4 including: means to positively connect locking members of selected latch assemblies so said locking members move in unison.
 7. The latching system defined in claim 6 wherein said selected latch assemblies have the axes of rotation of said star wheels thereof in substantial alignment.
 8. The latching system defined in claim 6 wherein said selected latch assemblies are substantially aligned in the direction of movement of the pallets. 